In general, a chart may be a simple list of content items in no particular order. Examples of items include music and other audio content, video items, text files and more. In some embodiments described in more detail below, the term “chart” refers to a ranking of content according to popularity over a given period of time or according to editorial expertise. Examples of popularity charts published in the music industry include: the Billboard 100, MW Club Charts, Hot 100 or Top 40. Charts exist for other types of content such as books (including audio books), journals, games audio, visual and social/community based educational services, lessons and courses capable of being supported with physical, printed and online materials and much more and the term used herein is not intended to be limited to music unless expressly so limited. Charts may be compiled for example on different measures of popularity, different chapters read or different modules completed, for example retail purchases, download or streaming.
In some embodiments described in more detail below, content items are referred to as “tracks”. The term “tracks” is not limited to music tracks unless expressly so limited and also encompasses other audio content, video items, text files and other consumable content.